Tobacco advertising is accepted by tobacco control advocates as playing a critical role in promoting adolescent smoking initiation, and current public policy goals in tobacco control include restricting or eliminating tobacco advertising. A major barrier to that goal has been the ability of the tobacco industry to argue that there are no data linking advertising to initiation and that advertising only influences brand preference. Examination of all tobacco advertising as a combined measure, diffuses the effects of specific targeted advertising campaigns on adolescent initiation. We will examine the association of three of those targeted campaigns (the Lucky Strike Campaign in the late 1920s, the Virginia Slims campaign in the late 196Os and the Camel Cartoon campaign in the late 1980s) in relation to their association with adolescent initiation and sales of the advertised brand. We will examine the temporal association, strength, coherence and specificity of these associations to determine whether they meet the criteria of a causal relationship. In a companion analysis we will examine the effect of media-led tobacco control efforts on long-term cessation. We will quantify the effect of age and cost of cigarettes on cessation rates across birth cohorts of the U.S. population and demonstrate an independent calendar year effect for the calendar years 1967-70 (the period of free counter-advertising in response to tobacco advertising on the broadcast media) on long-term successful cessation across multiple birth cohorts. We will also examine the tobacco control campaign in California to demonstrate the effect of its media-led campaign on long-term cessation.